Diffusion tensor imaging and quantitative T2 mapping to monitor muscle recovery following hamstring injury

MRI examinations are accurate for diagnosing sports-related acute hamstring injuries. However, sensitive imaging methods for assessing recovery of these injuries are lacking. Diffusion tensor imaging (DTI) and quantitative T2 (qT2) mapping have both shown promise for assessing recovery of muscle micro trauma and exercise effects. The purpose of this study was to explore the potential of DTI and qT2 mapping for monitoring the muscle recovery processes after acute hamstring injury. In this prospective study, athletes with an acute hamstring injury underwent a 3-T MRI examination of the injured and contralateral hamstrings including DTI and qT2 measurements at three time points: (1) within 1 week after sustaining the injury, (2) 2 weeks after time point 1, and (3) return to play (RTP). A linear mixed model was used for time-effect analysis and paired t-tests for the detection of differences between injured and uninjured muscles. Forty-one athletes (age 27.8 ± 7 years; two females and 39 males) were included. Mean RTP time was 50 (range 12–169) days. A significant time effect was found for mean diffusivity, radial diffusivity, and the second and third eigenvalues (p ≤ 0.001) in the injured muscles. Fractional anisotropy (p = 0.40), first eigenvalue (p = 0.02), and qT2 (p = 0.61) showed no significant time effect. All DTI indices, except for fractional anisotropy, were significantly elevated compared with control muscles right after the injury (p 0.04). In conclusion, DTI can be used to monitor recovery after an acute hamstring injury. Future work should explore the potential of DTI indices to predict RTP and recovery times in athletes after an acute strain injury

Nonfocal transient neurological attacks are related to cognitive impairment in patients with heart failure

Introduction Nonfocal transient neurological attacks (TNAs) are associated with an increased risk of future dementia, but it is unclear whether TNAs are also associated with concurrent cognitive impairment. We hypothesized that recent TNAs are related to worse cognitive functioning. We tested our hypothesis in patients with heart failure, as these patients are at risk of cerebral hypoperfusion, which might play a role in the etiology of TNAs. Methods We performed neuropsychological testing in all patients with heart failure enrolled in the Heart Brain Connection study. We assessed global cognition, attention-psychomotor speed, executive functioning, memory and language. All patients were interviewed with a standardized questionnaire on the occurrence of TNAs in the preceding 6 months. We studied associations between TNAs and cognitive functioning with linear and logistic regression analyses, adjusted for age, sex and education. We performed additional analyses in patients without previous stroke or TIA and in patients without brain infarction on MRI. Results Thirty-seven (23%) of 158 patients (mean age 70 years, 67% men) experienced one or more TNAs. Patients with a recent TNA were more likely to be impaired on≥1 cognitive domains than patients without TNAs [41% vs. 18%, adjusted odds ratio 4.6, 95% confdence interval (CI) 1.8–11.8]. Patients with TNAs performed worse than patients without TNAs on global cognition (mean diference in z scores −0.36, 95% CI −0.54 to −0.18), and on the cognitive domains attentionpsychomotor speed (mean diference −0.40, 95% CI −0.66 to −0.14), memory (mean diference −0.57, 95% CI −0.98 to −0.15) and language (mean diference −0.47, 95% CI −0.79 to −0.16). These associations were independent of cardiac output and volume of white matter hyperintensities. Subgroup analyses in patients without previous stroke or TIA or brain infarction on MRI (n=78) yielded comparable results, with the exception of the cognitive domain language, which was no longer diferent between patients with and without TNAs. Conclusion Among patients with heart failure, TNAs are associated with cognitive impairment, which warrants the need for more clinical awareness of this problem

Nonfocal transient neurological attacks in patients with carotid artery occlusion

Introduction: Nonfocal transient neurological attacks (TNAs) are episodes with atypical, nonlocalizing cerebral symptoms. We examined the prevalence of nonfocal TNAs, in patients with and without carotid artery occlusion (CAO). Methods: We included 67 patients with CAO and 62 patients without CAO. In both groups, patients had a history of transient ischemic attack (TIA) or nondisabling ischemic stroke in the anterior circulation that had occurred >6 months before inclusion. Patients without CAO did not have ipsilateral or contralateral carotid artery stenosis of ≥50%. All patients were interviewed with a standardized questionnaire on the occurrence of nonfocal TNA symptoms during the preceding six months. We calculated risk ratios (RRs) with 95% confidence intervals (CIs) for the occurrence of ≥1 and ≥2 different nonfocal TNAs after adjustments for age, sex, systolic blood pressure and time interval between most recent TIA or ischemic stroke and administration of the questionnaire. Results: Forty-three of all patients (33%) had had one or more nonfocal TNAs in the preceding six months. Nonrotatory dizziness (24%) was reported most often. The prevalence of ≥1 nonfocal TNAs was not significantly different between patients with and without CAO (39% vs. 27%; adjusted RR 1.47, 95% CI 0.83–2.61), but the prevalence of ≥2 or more different nonfocal TNAs was higher in patients with CAO (16% vs. 3%; adjusted RR 4.77, 95% CI 1.20–18.98). In patients with CAO who also had a contralateral carotid or vertebral artery steno-occlusion, nonfocal TNAs occurred more often than in patients without any carotid or vertebral artery steno-occlusion (46% vs. 27%; adjusted RR 2.22, 95% CI 1.08–4.60 for ≥1 and 21% vs. 3%; adjusted RR 8.27, 95% CI 1.83–37.32 for ≥2 nonfocal TNAs). Conclusions: Patients with CAO more often experienced multiple nonfocal TNAs than patients without CAO

Nonfocal transient neurological attacks in patients with carotid artery occlusion

Introduction: Nonfocal transient neurological attacks (TNAs) are episodes with atypical, nonlocalizing cerebral symptoms. We examined the prevalence of nonfocal TNAs, in patients with and without carotid artery occlusion (CAO). Methods: We included 67 patients with CAO and 62 patients without CAO. In both groups, patients had a history of transient ischemic attack (TIA) or nondisabling ischemic stroke in the anterior circulation that had occurred >6 months before inclusion. Patients without CAO did not have ipsilateral or contralateral carotid artery stenosis of ≥50%. All patients were interviewed with a standardized questionnaire on the occurrence of nonfocal TNA symptoms during the preceding six months. We calculated risk ratios (RRs) with 95% confidence intervals (CIs) for the occurrence of ≥1 and ≥2 different nonfocal TNAs after adjustments for age, sex, systolic blood pressure and time interval between most recent TIA or ischemic stroke and administration of the questionnaire. Results: Forty-three of all patients (33%) had had one or more nonfocal TNAs in the preceding six months. Nonrotatory dizziness (24%) was reported most often. The prevalence of ≥1 nonfocal TNAs was not significantly different between patients with and without CAO (39% vs. 27%; adjusted RR 1.47, 95% CI 0.83–2.61), but the prevalence of ≥2 or more different nonfocal TNAs was higher in patients with CAO (16% vs. 3%; adjusted RR 4.77, 95% CI 1.20–18.98). In patients with CAO who also had a contralateral carotid or vertebral artery steno-occlusion, nonfocal TNAs occurred more often than in patients without any carotid or vertebral artery steno-occlusion (46% vs. 27%; adjusted RR 2.22, 95% CI 1.08–4.60 for ≥1 and 21% vs. 3%; adjusted RR 8.27, 95% CI 1.83–37.32 for ≥2 nonfocal TNAs). Conclusions: Patients with CAO more often experienced multiple nonfocal TNAs than patients without CAO

Nonfocal transient neurological attacks are related to cognitive impairment in patients with heart failure

Introduction: Nonfocal transient neurological attacks (TNAs) are associated with an increased risk of future dementia, but it is unclear whether TNAs are also associated with concurrent cognitive impairment. We hypothesized that recent TNAs are related to worse cognitive functioning. We tested our hypothesis in patients with heart failure, as these patients are at risk of cerebral hypoperfusion, which might play a role in the etiology of TNAs. Methods: We performed neuropsychological testing in all patients with heart failure enrolled in the Heart Brain Connection study. We assessed global cognition, attention-psychomotor speed, executive functioning, memory and language. All patients were interviewed with a standardized questionnaire on the occurrence of TNAs in the preceding 6 months. We studied associations between TNAs and cognitive functioning with linear and logistic regression analyses, adjusted for age, sex and education. We performed additional analyses in patients without previous stroke or TIA and in patients without brain infarction on MRI. Results: Thirty-seven (23%) of 158 patients (mean age 70 years, 67% men) experienced one or more TNAs. Patients with a recent TNA were more likely to be impaired on ≥ 1 cognitive domains than patients without TNAs [41% vs. 18%, adjusted odds ratio 4.6, 95% confidence interval (CI) 1.8–11.8]. Patients with TNAs performed worse than patients without TNAs on global cognition (mean difference in z scores − 0.36, 95% CI − 0.54 to − 0.18), and on the cognitive domains attention-psychomotor speed (mean difference − 0.40, 95% CI − 0.66 to − 0.14), memory (mean difference − 0.57, 95% CI − 0.98 to − 0.15) and language (mean difference − 0.47, 95% CI − 0.79 to − 0.16). These associations were independent of cardiac output and volume of white matter hyperintensities. Subgroup analyses in patients without previous stroke or TIA or brain infarction on MRI (n = 78) yielded comparable results, with the exception of the cognitive domain language, which was no longer different between patients with and without TNAs. Conclusion: Among patients with heart failure, TNAs are associated with cognitive impairment, which warrants the need for more clinical awareness of this problem

The repeatability of bilateral diffusion tensor imaging (DTI) in the upper leg muscles of healthy adults

Objectives: Assessment of the repeatability of diffusion parameter estimations in the upper leg muscles of healthy adults over the time course of 2 weeks, from a simultaneous bilateral upper leg DTI measurement. Methods: SE-EPI DTI datasets were acquired at 3 T in the upper legs of 15 active adults at a time interval of 2 weeks. ROIs were manually drawn for four quadriceps and three hamstring muscles of both legs. The following DTI parameters were analyzed: 1st, 2nd, and 3rd eigenvalue (λ1, λ2, and λ3), mean diffusivity (MD), and fractional anisotropy (FA). DTI parameters per muscle were calculated with and without intravoxel incoherent motion (IVIM) correction together with SNR levels per muscle. Bland-Altman plots and within-subject coefficient of variation (wsCV) were calculated. Left-right differences between muscles were assessed. Results: The Bland-Altman analysis showed good repeatability of all DTI parameters except FA for both the IVIM-corrected and standard data. wsCV values show that MD has the highest repeatability (4.5% IVIM; 5.6% standard), followed by λ2 (4.9% IVIM; 5.5% standard), λ1 (5.3% IVIM; 7.5% standard), and λ3 (5.7% IVIM; 5.7% standard). wsCV values of FA were 15.2% for the IVIM-corrected data and 13.9% for the standard analysis. The SNR (41.8 ± 16.0 right leg, 41.7 ± 17.1 left leg) and wsCV values were similar for the left and right leg and no left-right bias was detected. Conclusions: Repeatability was good for standard DTI data and slightly better for IVIM-corrected DTI data. Our protocol is suitable for DTI of the upper legs with overall good SNR. Key Points: • The presented DTI protocol is repeatable and therefore suitable for bilateral DT imaging of the upper legs. • Additional B1+calibrations improve SNR and repeatability. • Correcting for perfusion effects improves repeatability

Cognitive functioning in patients with carotid artery occlusion; a systematic review

Introduction: Patients with complete occlusion of the internal carotid artery (CAO) are vulnerable to cerebral hypoperfusion. Since cerebral hypoperfusion is associated with accelerated cognitive decline, patients with CAO may have an increased risk of cognitive impairment. We aimed to assess the prevalence and profile of cognitive impairment in patients with CAO and to explore the relation between hemodynamic impairment and cognitive functioning. Methods: We systematically searched Medline and EMBASE for studies including patients with symptomatic or asymptomatic CAO subjected to cognitive testing that were published between 1980 and 2017. We did not include patients with carotid stenosis. We obtained data on type of study, patient characteristics, cerebral imaging and neuropsychological testing. In addition, we extracted data on potential causes of systemic hemodynamic impairment and the presence and stage of cerebral hemodynamic impairment. We assessed methodological quality of included studies with the Newcastle-Ottawa Scale. Results: We found eight studies comprising 244 patients (mean age 61 years, 76% male, 93% symptomatic CAO). The proportion of patients with cognitive impairment ranged from 54 to 71% in four studies; in the other four studies patients with CAO performed worse on cognitive testing than controls, but results were not quantified. Impairment was reported in all cognitive domains. We found no data on the association between systemic hemodynamic impairment and cognitive functioning. Studies that assessed whether cerebral hemodynamic impairment was associated with cognitive functioning showed conflicting results. Conclusion: In patients with CAO, cognitive impairment is present in about half to two-thirds of patients and is not restricted to specific cognitive domains. The effect of systemic and cerebral hemodynamic impairment on cognitive functioning in patients with CAO deserves further study

Cognitive functioning in patients with carotid artery occlusion; a systematic review

Introduction: Patients with complete occlusion of the internal carotid artery (CAO) are vulnerable to cerebral hypoperfusion. Since cerebral hypoperfusion is associated with accelerated cognitive decline, patients with CAO may have an increased risk of cognitive impairment. We aimed to assess the prevalence and profile of cognitive impairment in patients with CAO and to explore the relation between hemodynamic impairment and cognitive functioning. Methods: We systematically searched Medline and EMBASE for studies including patients with symptomatic or asymptomatic CAO subjected to cognitive testing that were published between 1980 and 2017. We did not include patients with carotid stenosis. We obtained data on type of study, patient characteristics, cerebral imaging and neuropsychological testing. In addition, we extracted data on potential causes of systemic hemodynamic impairment and the presence and stage of cerebral hemodynamic impairment. We assessed methodological quality of included studies with the Newcastle-Ottawa Scale. Results: We found eight studies comprising 244 patients (mean age 61 years, 76% male, 93% symptomatic CAO). The proportion of patients with cognitive impairment ranged from 54 to 71% in four studies; in the other four studies patients with CAO performed worse on cognitive testing than controls, but results were not quantified. Impairment was reported in all cognitive domains. We found no data on the association between systemic hemodynamic impairment and cognitive functioning. Studies that assessed whether cerebral hemodynamic impairment was associated with cognitive functioning showed conflicting results. Conclusion: In patients with CAO, cognitive impairment is present in about half to two-thirds of patients and is not restricted to specific cognitive domains. The effect of systemic and cerebral hemodynamic impairment on cognitive functioning in patients with CAO deserves further study

The relationship between quantitative magnetic resonance imaging of the ankle plantar flexors, muscle function during walking and maximal strength in people with neuromuscular diseases

Background: Progression of plantar flexor weakness in neuromuscular diseases is usually monitored by muscle strength measurements, although they poorly relate to muscle function during walking. Pathophysiological changes such as intramuscular adipose tissue affect dynamic muscle function independent from isometric strength. Diffusion tensor imaging and T2 imaging are quantitative MRI measures reflecting muscular pathophysiological changes, and are therefore potential biomarkers to monitor plantar flexor functioning during walking in people with neuromuscular diseases. Methods: In fourteen individuals with plantar flexor weakness diffusion tensor imaging and T2 scans of the plantar flexors were obtained, and the diffusion indices fractional anisotropy and mean diffusivity calculated. With a dynamometer, maximal isometric plantar flexor strength was measured. 3D gait analysis was used to assess maximal ankle moment and power during walking. Findings: Fractional anisotropy, mean diffusivity and T2 relaxation time all moderately correlated with maximal plantar flexor strength (r > 0.512). Fractional anisotropy and mean diffusivity were not related with ankle moment or power (r < 0.288). T2 relaxation time was strongly related to ankle moment (r = −0.789) and ankle power (r = −0.798), and moderately related to maximal plantar flexor strength (r < 0.600). Interpretation: In conclusion, T2 relaxation time, indicative of multiple pathophysiological changes, was strongly related to plantar flexor function during walking, while fractional anisotropy and mean diffusivity, indicative of fiber size, only related to maximal plantar flexor strength. This indicates that these measures may be suitable to monitor muscle function and gain insights into the pathophysiological changes underlying a poor plantar flexor functioning during gait in people with neuromuscular diseases